Grinder for the cutters of pencil sharpeners



' June. 1927' G. E. BURTON GRINDER FOR THE CUTTERS OF PENCIL SHARPENERS Filed A112. 25. 1923 1? aiil 11mm 'lllllm IN VBYT 0R.

. 1,; ATTORNEY.

Patented June 28 1927.

UNITED STATES cnonen n. BURTON, or PHILADELPHIA, PENNSYLVANIA.

GRINDER FOR THE CUTTERS OF PENCIL SHARPENERS.

Application filed August 25, 1923, Serial No. 659,297.

This invention relates to devices for grinding the rotary cutters of Boston, Dexter and similar well known typesof pencil sharpeners; and, it has for its primary obj ect to provide a novel combmation pencil pointer .and cutter grinder n a unlta-ry structure. Incidentally, it 1s a well known fact that pencil sharpeners of the types referred to very speedily become inetficient and practically worthless for the purpose of properly pointing and sharpening pencils owing to the rapidity with which the rotary cutters lose their cutting edges and ability to produce a clean out upon both the lead and wood portions of an ordinary pencil. t

. More particularly my present, invention has reference to grinders or sharpeners for rotary cutters of the character set forth my prior Patent 1,l33,339, dated October 24;, 1922, although it is to be noted that it is not limited thereby.

Generally expressed my present invention aims to provide a grinder of the referred to type which is an associated part of the pencil pointer proper, the same being adapted for movement into, and-out of, operative position by an inexperienced person with perfect case. 7

In other words, my novel form of grinder can be snapped into the operative position, and similarly removed therefrom by a simple actionor pull of the operators fingers.

To the attainment of the foregoing end-s, my invention embraces a pair of spring influenced-arms supporting abrading members, said armsbeingfpivotally mounted in juxtaposition to the rotary cutters and adapted for retention in positions below and above the axis of their pivot .01 a common dead center.

In the further disclosure of the invention,

' reference will be made to the accompanying sheet of drawings forming a part hereof and in which like characters designate the same or corresponding parts in all the views. Figure 1 is a to plan view of a pencil pointer constructec in accordance with the. present invention, with the chip receptacle removed.

Figure-2 isa front end elevation of the same. Figure 3 is a perspective view of .one of the spring influenced arms hereinafter more particularly described. a Figure 4 is a perspective view of one of the abrasive holders; and

explained. I

Figure 5 ter holder.

Referring more particularly to the drawings in detail, thestandard of an ordinary Boston pencil sharpener is designated by the numeral 6, the same having a foot portion 7 and integral head 8 constituting a bearing for the cutter carrier, hereinafter generally referred to by the numeral 9. The foregoing'parts are but briefly referred to seeing they are in the main constructed in accordance with well known patterns with the exception of the cutter carrier 9. This cutter carrier 9 it will be best seen from Figure 5 comprises a head 10 having an integral spindle 11 for j'ournaling in the aforesaid standard head 8, and attachment thereto of the customary operating handle 12.

Longitudina lly extending fromthe cutter carrier head 10 are inwardly converging brace members 13, 14 respectively, that merge into the cross bar 15, from which pro jects the tubular pencil-guiding portion 16. The rotary cutters are designated by the numeral 1 7Figures 1 and 2and they are in accordance with anywell known form or pattern.

Outwardly projecting in parallel planes from the brace member 13 and at right angles to' the longitudinal axis of the cutter carrier 9 are a pair of lugs 18, 18 having oo-axial holes 19, 19 for the reception of a pivot pin 20. These lugs 18, 18 it'will be observed are formed at their .outer rounded portions with reversely cut-away parts constituting stops 21, for a purpose hereafter is a perspective view of the cut- Piyotally mounted on the aforesaid pin 20 are a pair of reversely directed and sub stantially T-shaped arms 22, one of which is shown in Figure 3;; and in view of the fact that said arms are duplicates with the exception of being right and left-hand in so far as their assemblage is concerned, I will only describe one fully. These arms 22 as best seen from Figure 3, each comprise a main leg'23 adapted for pivoting on the aforesaid pin 20 through the medium of a hole 24:, and it is to be particularly observed that this leg 23 is formed with a laterally directed projection-25 at its upper part. This lateral projection 25 is the detail above referred to that constitutes the right and left handdistinguishing feature when the parts are assembled; in that it is located to one side of the leg 23 of the one arm 22 and on the opposite side of the leg 23 of the other arm, as clearly shown by Figure 1. Extended in both directions and at right angles to the leg 23 is the integral cross arm 26 that is formed at its free ends with shouldered pins 27 for a purpose hereafter explained, while each said arm 26 is formed with a similarly-shaped shouldered button 28 in line with the leg 23.

Pivotally mounted on the shouldered but tons 28 are the abrading element holders, comprehensively designated by the numeral 29, and one of which is specifically illustrated in Figure 1. Each abrading element holder 29 is preferably made from a sheet metal blank medially folded upon itself at 30 to provide a reinforced bearing portion 31, which is apertured at 32 for pivotal support upon the associated button 28, whereon it is retained by means of a snap ring 33. From the aforesaid medial portion 30 the blank is laterally bent in opposed directions to furnish a back 34 that pro vided with angled gripping members 35 between Which the abrasive or other suitable grinding material block 36 is securely clamped and supported.

Contractile springs 37 provided with eyed ends are fitted on the aforesaid shouldered pins 27, and it will be perfectly obvious from an inspection of Figure 2 more particularly, that when the abrasive blocks 36 are in conthe rotary cutters 17, the springs 37 are disposed below or inwards with regard to the pivot pin 20, or dead center line, thereby ensuring an efficient flexible pressure upon said cutters 17 for grinding pur oses. On the other hand if an outward pul is exerted upon the shouldered buttons 28, with respect to the rotation of the cutter carrier 9 the abrading elements 36 will be moved away from the rotary cutters 17 and When the springs 37 pass beyond the center of the pivot pin 20, the arms will be moved out- Wardly until the shoulders 25 engage the shoulders 21 and be held in such position by the action of the springs with the grinding stones held free of the cutters for ordinary pencil pointing purposes. Furthermore, when the abrading elements 36 are in contact with the rotary cutters 17, a turning of the operating handle 12 in a contraclockwise direction-by preference-will result in said rotary cutters 17 being completely ground or resharpened over their entire length by a simple operation, analogous to the ordinary operation of pointing a lead pencil, crayon or the like. Contrariwise, when the parts 36, 17 are not in contact as just described, it will be quite apparent that, the device will function as an ordinary pencil or crayon pointer in the ordinary and well known manner, while the parts 21, 25 will co-act to prevent outward movement of the arms 22 beyond the conlines of the chip holdernot shown.

Furthermore, by employing my present invention, and grinding the rotary cutters 17 at frequent intervals, the necessity of purchasing a new pencil sharpener or pointeror new cutters-is dispensed with; whereas, a device litted with my novel grinders 36 will give the maximum efficiency until the cutters thereof are so far worn down that further use is impossible.

While there has been shown and fully described a preferred embodiment of my invention, the same is not to be too conservativeiy construed, in that changes of the minor details and other applications thereof are permissible; provided, of course, such changes and modifications fairly fall within the scope of the sub-joined claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In a pencil sharpener having a rotary carrier and rotary cutters therein, of grinders rotated with said carrier and movable into and out of engagement with said cutters, and means for holding said grinders in either position.

2. In a pencil sharpener having a rotar carrier and rotary cutters therein, of a grin ing device comprising a pair of arms pivot-- ally mounted on the carrier, grinding elements carried by said arms and movable into and out of engagement with said cutters, a spring for holding said grinding elements in ,ither position,-and means for limiting the movement of said elements away from the cutters.

In a pencil sharpener having rotary cutters and a carrier therefor, the combination of supporting means on said carrier, opposedly directed arms pivotally mounted on said supporting means, abrading'means rockably carried by the arms, and means serving'to flexibly retain the abrading means in the operative and in theinoperative positions' 1 4. In a pencil sharpener having rotary cutters and a carrier therefor, the combina tion of a radially directed support, arms pivotally mounted on said support, abrading means rockably carried at the outer ends of the arms, contractile means serving to flexibly hold the arms and abrading means in the operative and inoperative positions, and means for limiting the outward movement of said arms when thrown to inoperative position.

5. In a grinding device for the rotary cutters of pencil sharpeners having a cutter carrier radially directed supporting lugs provided with reversely directed stops, grinder supporting arms pivoted to said lugs, and means on said arms coacting with said stops for limiting the movement of said arms in one direction.

6. In a grinding device for the rotary cutters of pencil Sharpeners, grinder supporting arms mounted on a common pivotal axis and having lateral projections and springs connecting the lateral projections of each arm and adapted to hold the arms in operative or inoperative position.

7. In a grinding device for the rotary cutters of pencil sharpeners, grinder supporting arms mounted on a common pivotal axis and provided each With a cross bar and a lateral projection on the body of the arm, springs connecting the terminal ends of the cross bars of each arm and adapted to hold the arms in ope ative or inoperative position, and means coacting with the lateral projections for limiting the movement of said arms in one direction. 7

8. A grinding attachment for the rotary cutters of pencil sharpeners comprising a rotatable supporting means, opposedly directed arms pivotally mounted on said supporting means, abrasive holders rockably mounted at the free ends of said'arms, means remova'bly retaining said holders in position, contractile means tending to hold said arms in operative or inoperative position and means serving to limit their movement When thrown to an inoperative position.

In testimony whereof I aflix my signature this 23rd day of August, 1923.

GEORGE E. BURTON. 

